<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
      <button type="button">普通的按钮</button>
      <hr>
      <form action="" method="GET">
       <label for="">用户名:</label>
       <input type="text" id='username'><br>
       <label for="">密码</label>
       <input type="password" id='pwd'><br>

       <button type="submit">提交</button>
      </form>
    
</body>
</html>
<script>
    /*
     js操作表单：

     

    */

</script>